Possible Duplicate:
Double underscore in PHP
In a PHP application that I am inheriting, there exist these code snippets which I have trouble comprehending:
$foo = bar(array(
'format' => '',
'prev_text' => __('«'),
'next_text' => __('»'),
));
And another example:
$some_text = sprintf( '<span>' . __( 'Displaying %s–%s of %s' ) . '</span>%s',
number_format_i18n( ( $current_page - 1 ) * $per_page + 1 ),
number_format_i18n( min( $current_page * $per_page, $total ) ),
number_format_i18n( $total ),
$page_links
);
What are those double underscores? I tried looking for a method whose name is just a double underscore but found none. What might that be, then?